Does A Tankless Gas Water Heater Need A Dedicated Circuit?

Does A Tankless Gas Water Heater Need A Dedicated Circuit?

Perhaps your old tank-style water heater recently reached the end of its lifespan, so now it’s time for a replacement. As you search for the best water heaters, you come across tankless water heaters. They’re a newer, convenient alternative to traditional-style water heaters, but are they any good?

Key Points:

  • Tankless water heaters are more efficient and expensive than traditional tank-style water heaters.
  • Tankless water heaters require a 120 volts AC, 60 Hz circuit with a maximum of 150 amperes.
  • Experts should be consulted when dealing with electrical installation requirements for tankless gas water heaters.

Tankless water heaters have their merits, but the requirements for a tankless water heater look a bit different than a traditional water heater. Here’s what you need to know.

What Is A Tankless Water Heater?

Tankless water heaters are exactly what they sound like – they’re water heaters without tanks. Traditional water heaters require a tank that holds hot water all the time in case you need hot water. Tankless water heaters, on the other hand, heat water on demand.

Since they only produce hot water as you need it, tankless water heaters are usually much more efficient than their counterpart. However, this efficiency comes at a cost, as tankless water heaters are generally three times as expensive as their tank-style counterpart.

How Do Tankless Water Heaters Work?

The inner workings of tankless water heaters are relatively simple. Instead of heating water in a large tank to keep up with demands, a tankless system heats water instantaneously without using a tank.

When you turn on the hot water side of a faucet in your home, cold water begins moving through the water heater system. As it passes through the heat exchanger in the unit, a natural gas burner or an electric element (in electric water heaters) heats the water.

So, instead of waiting for the tank on a traditional heater to heat up, the process happens as you need hot water. While this is an excellent alternative to tank-style water heaters, tankless water heaters can be overwhelmed by demand when you have multiple taps on at once. From a technical standpoint, they can’t technically run out of hot water because they heat water on demand.

But, you might notice the water doesn’t get as hot when multiple taps in your home are demanding hot water at the same time.

What Are The Electrical Requirements For A Gas Tankless Water Heater?

Specific electrical requirements for tankless gas water heaters vary based on your location, as it depends on whether you live in an area with 220 volts or 110 volts power supply. The unit’s circuit electrical requirements will be sized using the wattage of the particular unit.

However, the National Electrical Code outlines specific requirements across the board for tankless gas water heaters. According to the NEC, these units need to be supplied with a 15 to 20-ampere 120-volt electrical circuit that provides power to the system’s ignition device and control board.

The settings of the particular circuit breaker determine the ratings of the circuit because the control circuit is an individual load. According to the NEC, instantaneous water heaters need to have circuits that don’t exceed 120 amperes and are protected at no more than 150 amperes.

Do Tankless Water Heaters Need A Dedicated Circuit?

Since gas tankless water heaters use minimal amounts of energy to ignite the flame to heat the water, there isn’t a need for a dedicated circuit to power the system. However, in some cases, manufacturers require installing a dedicated circuit for their tankless water heaters.

Tankless natural gas water heaters come with specific circuit requirements, so there’s no guesswork involved. For instance, consider a Rinnai tankless water heater. This particular brand usually requires 120 volts AC, 60 Hz, and less than three amps for its products. Of course, these requirements may vary based on the particular model, so be sure to check the installation instructions.

Unless you’re experienced with installing these systems, you should pass the process to a professional. So, if you have a technician install the unit and you already bought it, give them the installation instructions so they can access the specific requirements for that model.

Do You Need A GFCI Breaker For A Tankless Water Heater?

According to the National Electrical Code (NEC), there aren’t any GFCI requirements for water heater installations, including tankless models. However, there are a few exceptions to these rules.

Generally, the receptacle the water heater plugs into should be protected by a GFCI breaker only when it’s within 6 feet of a sink, in a garage, or outdoors. However, in most homes, the water heater resides in the basement, tucked away in an inconspicuous location (like a maintenance room).

Additionally, if the receptacle requires GFCI protection, you’ll need it regardless of whether you plug a water heater into it or not.

Frequently Asked Questions (FAQs)

Can I Install A Tankless Water Heater Myself?

While you could DIY your tankless water heater installation, it’s not a good idea if you’re inexperienced in this industry. You should avoid handling the installation process unless you’re a trained professional.

Installing a tankless water heater requires experience in numerous fields, including plumbing, electrical, heating, ventilating, and carpentry skills. On top of that, you need to familiarize yourself with state and local building codes, obtain the necessary permits to complete the work, and set up an inspection with your municipality.

So, it’s usually best to leave this project to the professionals. Hiring a professional can be an expensive addition to your project, but it’s worth the extra money to pay an experienced individual. Generally, hiring a professional to install a tankless water heater in your home will cost you anywhere from $500 to $1,500, not including the cost of the unit (usually between $500 and $2,000). On average, the entire process, installation, and unit included, costs about $2,800.